Generally, a reinforced concrete (RC) construction, a steel-frame (SF) construction, and a steel-framed reinforced concrete (SRC) construction are typically used to construct buildings. In recent years, as buildings are large-sized and high-storied, a combination of three constructions has been widely used.
Furthermore, as buildings are large-sized and high-storied, an earthquake-resistance and wind-resistance design becomes a major issue when constructing the buildings. Therefore, a core portion in which facilities such as an elevator, electric facility, system facility, and a staircase are arranged is firstly constructed using the reinforced concrete construction, and then a main column portion for defining residence spaces is secondly constructed using the steel-frame construction.
FIGS. 1 and 2 show a conventional structure for constructing a building having an SRC structure in which a core is constructed in advance.
In the drawings, the reference numeral 1 indicates a building core. As described above, the core 1 is constructed in advance using the RC construction considering the wind-resistance.
Typically, a tower crane and a concrete distributor are installed in an inner space of the core 1, and core dedicated facilities such as a hoist are installed outside the core 1.
A reinforcing bar 3 is arranged after a system foam is mounted using the core-dedicated facilities, and then a concrete 5 is placed to build the core in advance. Here, an anchor member 7 is buried and installed together when the concrete 5 is placed to prepare the construction of the steel-frame structure. The anchor member 7 includes a connection member 7a buried in the concrete 5, an anchor plate 7b welded to the connection member 7a, and a gusset plate 7c welded to the anchor plate 7b. 
Thereafter, a steel-frame beam 9 is assembled with the gusset plate 7c by using high tension bolts 7d, and then a slab 11 is built and constructed by installing a slab type mold, arranging reinforcing bars, and placing concrete on the basis of the steel-frame beam 9.
However, in the conventional method for constructing a building using the SRC construction in which the core is firstly build in advance, dedicated facilities such as the hoist and the concrete distributor may be required to arrange the reinforcing bar and place the concrete. In addition, the dedicated facilities should be removed for the installation of the steel frame, the arrangement of the reinforcing bar for slab, and the placing of the concrete, thereby complicating the construction process and increasing the construction costs.
Also, since the advanced core has a small size than that of the residence space defined by the slab, which will be constructed after the core, it is difficult to manage the manpower, manual tool and equipments. Furthermore, the core and the slab should be constructed by separately placing concrete, a reinforcing bar connecting the core to the slab have to be installed in walls in advance, thereby further increasing the construction costs. Also, the separate placement of the concrete is apt to deteriorate the quality of the buildings. In addition, since the working processes for the core and the slab should be done remotely in a vertical direction, the construction process is complicated, and the process, quality, safety managements are difficult.
Particularly, since there is no approaching path to the anchor member for installing the steel frame, the worker may primarily fix the steel frame to a steel-frame column of an outer peripheral portion, and then be moved toward the wall of the core with the help of a life rope installed on a safety rail constructed on the steel frame to secondarily fix the steel frame so as to install the steel frame on the anchor member. As a result, since the working process is cumbersome and the construction period is relatively longer, additional equipment for correcting should be essentially deployed, and safety management may be difficult.
To solve the problems according to the related art, this applicant have applied a construction method in which a core of a building and a steel frame for slab are constructed in advance, and then slab and core concrete are placed together with each other, or the slab concrete is placed in advance and then the core concrete is placed to improve qualities of core and slab structures, improve construction and safety, and reduce construction costs. Also, the construction method applied by this applicant has been patented. In recent, the construction method is being applied in large-scale high-rise build construction sites.
Also, in the conventional SRC structure construction technologies, a core which is prevailing in recent has a pure RC structure, and an outer peripheral portion has a steel-frame structure. Thus, the core should be constructed in advance. There are a conventional core advanced construction method and steel-frame advanced construction method, which is mainly applied to middle or low-rise buildings in the past, in which a steel-frame column and beam are installed in a wall of a core. In case of the core advanced construction method, an angle is previously installed in an RC core wall constructed in advance by using a set anchor to install a deck plate, and then, a deck is installed and concrete is placed. Here, the previously installed angle is not removed. Also, in the steel-frame advanced construction method, an angle is never installed, or since an angle for supporting a slab is welded to a girder, the angle is integrated with concrete after the concrete is cured. As a result, it may be difficult to recycle the angle.
Actually, after the concrete is cured, the angle for supporting the slab may be reduced. However, according to the conventional two methods, since the angle is never installed or is not removed, the angle may be retained. Thus, the construction costs may be increased, and also, it may be difficult to easily install an outer frame of the core for placing the core wall concrete.